A Tribute to Steen Duelund 1943-2005

Without the inspirational presence of Danish loudspeaker legend Steen Duelund, fondly known to the cognoscenti as the mad loudspeaker professor, the Gryphon Cantata, Poseidon and Trident would be very different loudspeakers, indeed they might not even exist at all.

A mathematician by training, Duelund dedicated his professional life to experimental loudspeaker design. He emerged from academic obscurity in the 1970’s when a do-it-yourself construction known as the Duelund cement horn was published in the Danish audio journal High Fidelity.

Generous to a fault, Duelund made his theoretical studies and practical applications freely available to anyone who had the necessary skill and courage to embark on such an undertaking. Among his greatest fans was the equally controversial Harvey Rosenberg of OTL (OutputTransformerless) amplifier fame.

Meeting by chance, Gryphon founder Flemming E. Rasmussen and Duelund recognized in each other kindred spirits – Duelund’s take no prisoners approach to loudspeaker design being completely in sync with Rasmussen’s amplifier philosophy.

Having followed his work closely, Flemming E. Rasmussen was curious as to why none of Duelund’s speaker designs or design concepts had ever become an actual commercial product. Flemming would find out soon enough.

Rasmussen and Duelund began from scratch with driver design, literally building by hand drivers with baskets that did not introduce compression, hand-made multi-laminate cones, exotic home-brew coatings, adjustable wire suspensions to replace the conventional spider, heavy-duty magnetic systems, ventilated pole pieces, machined phase plugs and special surrounds to optimize the transition between cone and baffle. All edges were beveled for an aerodynamic profile. Double wiring was employed on the cones to ensure perfect symmetry. The list of breakthroughs goes on.

Duelund’s revolutionary theories on constant phase in crossover networks can be summed up in a single statement: “All drivers must be in phase at all times at all frequencies.”

We are the proud to say that the Gryphon Cantata, Poseidon and Trident are the only speakers that live up to this theoretical ideal.

Following a long period of illness, Steen Duelund passed away on April 26, 2005.

To honor the memory of Duelund Gryphon has issued a competition to bring forward products that in one way or the other have been inspired by Steen Duelund.